Treating Rheumatoid Arthritis (RA) is a crucial challenge for the health systems. RA is the most common inflammatory arthritis, affecting 0.5% to 1% of the general population worldwide with little variation of the prevalence among countries.The current pharmacological management of RA involves early intervention with synthetic disease modifying anti-rheumatic drugs (DMARDs) either singly or in combination. Despite all those treatments, RA remains as an unmet clinical need where several concerns about long term treatments based on biologics have been arisen (Bongartz, 2009) while there are still approximately 20-40% of rheumathoid arthritis patients that do not have an adequate response to anti-TNF (Vander CB, 2006).The preclinical data obtained by the REGENER-AR consortium in a RA efficacy model in mice using allogeneic eASCs by intravenous route, demonstrated that mesenchymal expanded adult stem cells (eASC) extracted from adipose tissue have a large potential for treating RA.REGENER-AR consortium has defined a clinical translational project which aim is to develop a broadly available and clinically applicable treatment for RA by exploiting the biology of living human eASCs. To do that, the consortium is developing an Advanced Therapy Medicinal Product (ATMP) based on allogeneic eASCs for the treatment of RA (product internal code, Cx611) and ready for starting the clinical research (IMPD and clinical protocol has been approved by the regulatory agencies in January 2011).To accomplish this goal, it will be necessary to test this product through a phase Ib/IIa clinical trial in order to define the safety and feasibility of the systemic administration of allogeneic eASCS in patients with RA, but it will be necessary as well to advance in the difficulties that prevent cell therapy to be considered as a largely available product in the market facing several issues related to the production scale-up, effectively clinical treatment and regulatory affairs compilance